Rainbow Papaya story
Rainbow papaya

Dr. Garritt P. Wilder, a botanist at the Bishop Museum, is credited with introducing the Solo papaya in Hawaii to 1910. This marked one of the giant steps in papaya breeding in Hawaii, as Solo became the dominant type in commercial production.

The Hawaii papaya industry began suffering severe economic losses due to the impact of the devastating papaya ringspot virus on the island of Oahu as early as the 1950s. Papaya production then moved to the Puna area of the Big Island in the 1960s, but, by 1997, the virus had almost destroyed the papaya industry. Production of Hawaii's fifth largest crop fell by nearly 40 percent, farmers were going out of business, and Hawaii's once $17 million papaya industry was struggling to survive.

That same year, the U.S. government concluded its regulatory review of the first genetically engineered papaya variety named Rainbow, which is resistant to the papaya ringspot virus disease, and allowed about 200 small papaya farmers to begin planting the Rainbow papaya.

The Rainbow papaya is an F-1 hybrid variety of papaya produced by crossing Hawaii's yellow-flesh Kapoho Solo variety with the red-flesh SunUp. Researchers from Cornell University and the University of Hawaii had done research since 1984 to develop this Rainbow variety, which includes a gene that made the papaya plants resistant to the ringspot virus—similar to the way a vaccine makes people immune to disease.

Commercialized in 1998, the Rainbow papaya produced immediate results. Within four years, the genetic improvement had not only stopped the rapid decline of the Hawaii papaya industry, but production actually returned to levels near where they were before the papaya ringspot virus invasion.

Q: What is papaya ringspot virus?
A: Papaya ringspot virus is the most widespread and destructive virus disease of papaya. It belongs to the potyvirus group and is rapidly transmitted by a number of aphid species. There are two types, designated as PRSV-p and PRSV-w. PRSV-p infects papaya and many cucurbits such as squash and melons, while PRSV-w infects many cucurbits but does not infect papaya.

Q: How widespread is the papaya ringspot virus?
A: Papaya ringspot virus occurs nearly everywhere papaya grows. It has caused severe damage in nearly all the major papaya-growing areas of the world, including Brazil, Mexico, India, Thailand, Taiwan, Philippines, the southern region of China, and Hawaii.

Q: When did Hawaii's farmers begin growing Rainbow papaya?
A: Papaya farmers began planting Rainbow papaya in 1998 after a thorough review and approval for food and environmental safety by the U.S. government.

Q: What is the percentage of acreage of Rainbow papaya production in Hawaii?
A: Approximately 76 percent of the State's total bearing acreage is represented by Rainbow papaya. Kapoho Solo being harvested from 9% in 2009.

Q: When will Rainbow papaya be exported to Japan?
A: The Japanese government has completed the food and environmental safety assessments for Rainbow papaya, and has approved the importation of the Rainbow papaya starting December 1, 2011. The Rainbow papaya has begun to be exported to Japan.

Q: Will the Hawaii papaya industry stop exporting Kapoho Solo papaya to Japan?
A: No. The Hawaii papaya industry respects Japanese consumers' right to choose. The Hawaii papaya industry will also continue to supply the Japanese market with premium papaya, including conventionally bred varieties such as Kapoho Solo but will then offer another choice, the beautiful Rainbow papaya.

Q: Is Rainbow papaya safe for the environment?
A: Yes. Following a thorough assessment, both the U.S. Environmental Protection Agency (EPA) and USDA Animal and Plant Health Inspection Service (APHIS) determined Rainbow papaya posed no safety concerns for the environment. Rainbow papaya has completed an environmental review by Japan regulatory officials and has been determined safe for the environment. Rainbow papaya will be offered in Japan as another choice for the consumer.

Q: What benefits does the Rainbow papaya provide to Hawaii's farmers?
A: The Rainbow papaya has given Hawaii's farmers a second chance to be able to continue growing papaya. Prior to Rainbow papaya, the papaya ringspot virus disease had become so widespread that the Hawaii papaya industry was on the verge of extinction. Rainbow papaya offers farmers a choice for effectively producing Hawaii premium papaya in areas where the papaya ringspot virus continues to affect papaya plants.

Q: What is GMO?
A: GMO refers to a plant that has been genetically modified in order to impart certain desired qualities in a process that is like being vaccinated for diseases such as measles or polio. Dr. Maureen Fitch of the USDA, ARS, performed the original modification of papaya on the red variety called Sunrise. Pieces of the ringspot virus have been genetically inserted into the genetic makeup of the papaya to render it immune to that virus. The resulting papaya became known as the "Sunup." Subsequent crosses with the "Kapoho" resulted in the "Rainbow," a modified cultivar resistant to the papaya ringspot virus that is the most prevalent fruit on the market today.